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[PATCH v10 5/7] Row pattern recognition patch (docs). 265+ messages / 2 participants [nested] [flat]
* [PATCH v10 5/7] Row pattern recognition patch (docs). @ 2023-10-22 02:22 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Tatsuo Ishii @ 2023-10-22 02:22 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 80 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 170 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..cf18dd887e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,86 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. Row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. So in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. In the second or + subsequent rows all window functions and aggregates are NULL. For rows + that do not match the PATTERN, all window functions and aggregates are + shown AS NULL too, except count which shows 0. This is because the + unmatched rows are in an empty frame. Example of + a <literal>SELECT</literal> using the <literal>DEFINE</literal> + and <literal>PATTERN</literal> clause is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock, + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | + company1 | 2023-07-03 | 150 | | | + company1 | 2023-07-04 | 140 | | | + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | + company1 | 2023-07-08 | 130 | | | + company1 | 2023-07-09 | 120 | | | + company1 | 2023-07-10 | 130 | | | 0 +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 7c3e940afe..1d835af15a 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -21878,6 +21878,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -21917,6 +21918,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 42d78913cf..522ad9dd70 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sun_Oct_22_11_39_20_2023_140)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v10-0006-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
* [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source @ 2025-07-27 15:48 Lukas Fittl <[email protected]> 0 siblings, 0 replies; 265+ messages in thread From: Lukas Fittl @ 2025-07-27 15:48 UTC (permalink / raw) In passing also reduce the per-loop overhead caused by repeated divisions in INSTR_TIME_GET_NANOSEC when the ticks variable has become very large, instead diff first and then turn it into nanosecs. --- src/bin/pg_test_timing/pg_test_timing.c | 59 +++++++++++++++++++------ src/include/portability/instr_time.h | 30 ++++++++----- 2 files changed, 65 insertions(+), 24 deletions(-) diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c index a5621251afc..b77ef2063b6 100644 --- a/src/bin/pg_test_timing/pg_test_timing.c +++ b/src/bin/pg_test_timing/pg_test_timing.c @@ -16,6 +16,7 @@ static const char *progname; static unsigned int test_duration = 3; static double max_rprct = 99.99; +static bool fast_timing = false; /* record duration in powers of 2 nanoseconds */ static long long int histogram[32]; @@ -56,6 +57,7 @@ handle_args(int argc, char *argv[]) static struct option long_options[] = { {"duration", required_argument, NULL, 'd'}, {"cutoff", required_argument, NULL, 'c'}, + {"fast", no_argument, NULL, 'f'}, {NULL, 0, NULL, 0} }; @@ -68,7 +70,7 @@ handle_args(int argc, char *argv[]) { if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0) { - printf(_("Usage: %s [-d DURATION] [-c CUTOFF]\n"), progname); + printf(_("Usage: %s [-d DURATION] [-c CUTOFF] [--fast]\n"), progname); exit(0); } if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0) @@ -78,7 +80,7 @@ handle_args(int argc, char *argv[]) } } - while ((option = getopt_long(argc, argv, "d:c:", + while ((option = getopt_long(argc, argv, "d:c:f:", long_options, &optindex)) != -1) { switch (option) @@ -125,6 +127,10 @@ handle_args(int argc, char *argv[]) } break; + case 'f': + fast_timing = true; + break; + default: fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname); @@ -155,11 +161,31 @@ test_timing(unsigned int duration) uint64 total_time; int64 time_elapsed = 0; uint64 loop_count = 0; - uint64 prev, - cur; instr_time start_time, end_time, - temp; + prev, + cur; + char *time_source = NULL; + bool fast_timing_used = false; + + INSTR_TIME_INITIALIZE(); + +#if !defined(WIN32) && defined(__x86_64__) && defined(__linux__) + if (fast_timing && has_rdtsc) + { + time_source = "RDTSC"; + fast_timing_used = true; + } + else if (has_rdtscp) + time_source = "RDTSCP"; + else + time_source = PG_INSTR_CLOCK_NAME; +#else + time_source = PG_INSTR_CLOCK_NAME; +#endif + if (fast_timing && !fast_timing_used) + printf(_("Warning: Fast timing requested, but not available - regular timing source will be used\n")); + printf(_("Time source: %s\n"), time_source); /* * Pre-zero the statistics data structures. They're already zero by @@ -173,8 +199,11 @@ test_timing(unsigned int duration) total_time = duration > 0 ? duration * INT64CONST(1000000000) : 0; - INSTR_TIME_SET_CURRENT(start_time); - cur = INSTR_TIME_GET_NANOSEC(start_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(start_time); + else + INSTR_TIME_SET_CURRENT(start_time); + cur = start_time; while (time_elapsed < total_time) { @@ -182,9 +211,11 @@ test_timing(unsigned int duration) bits; prev = cur; - INSTR_TIME_SET_CURRENT(temp); - cur = INSTR_TIME_GET_NANOSEC(temp); - diff = cur - prev; + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(cur); + else + INSTR_TIME_SET_CURRENT(cur); + diff = INSTR_TIME_DIFF_NANOSEC(cur, prev); /* Did time go backwards? */ if (unlikely(diff < 0)) @@ -217,11 +248,13 @@ test_timing(unsigned int duration) largest_diff_count++; loop_count++; - INSTR_TIME_SUBTRACT(temp, start_time); - time_elapsed = INSTR_TIME_GET_NANOSEC(temp); + time_elapsed = INSTR_TIME_DIFF_NANOSEC(cur, start_time); } - INSTR_TIME_SET_CURRENT(end_time); + if (fast_timing) + INSTR_TIME_SET_CURRENT_FAST(end_time); + else + INSTR_TIME_SET_CURRENT(end_time); INSTR_TIME_SUBTRACT(end_time, start_time); diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h index e2e339a0c4f..f02296f1026 100644 --- a/src/include/portability/instr_time.h +++ b/src/include/portability/instr_time.h @@ -112,10 +112,13 @@ extern int64 max_ticks_no_overflow; */ #if defined(__darwin__) && defined(CLOCK_MONOTONIC_RAW) #define PG_INSTR_CLOCK CLOCK_MONOTONIC_RAW +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC_RAW)" #elif defined(CLOCK_MONOTONIC) #define PG_INSTR_CLOCK CLOCK_MONOTONIC +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_MONOTONIC)" #else #define PG_INSTR_CLOCK CLOCK_REALTIME +#define PG_INSTR_CLOCK_NAME "clock_gettime (CLOCK_REALTIME)" #endif #if defined(__x86_64__) && defined(__linux__) @@ -174,7 +177,7 @@ pg_get_ticks(void) } static inline int64_t -pg_ticks_to_ns(instr_time t) +pg_ticks_to_ns(int64 ticks) { /* * Would multiplication overflow? If so perform computation in two parts. @@ -183,7 +186,7 @@ pg_ticks_to_ns(instr_time t) */ int64 ns = 0; - if (unlikely(t.ticks > max_ticks_no_overflow)) + if (unlikely(ticks > max_ticks_no_overflow)) { /* * Compute how often the maximum number of ticks fits completely into @@ -192,7 +195,7 @@ pg_ticks_to_ns(instr_time t) * value. In a 2nd step we adjust the number of elapsed ticks and * convert the remaining ticks. */ - int64 count = t.ticks / max_ticks_no_overflow; + int64 count = ticks / max_ticks_no_overflow; int64 max_ns = max_ticks_no_overflow * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; ns = max_ns * count; @@ -201,11 +204,11 @@ pg_ticks_to_ns(instr_time t) * Subtract the ticks that we now already accounted for, so that they * don't get counted twice. */ - t.ticks -= count * max_ticks_no_overflow; - Assert(t.ticks >= 0); + ticks -= count * max_ticks_no_overflow; + Assert(ticks >= 0); } - ns += t.ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; + ns += ticks * ticks_per_ns_scaled / TICKS_TO_NS_PRECISION; return ns; } @@ -226,14 +229,14 @@ pg_initialize_get_ticks() #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_get_ticks()) -#define INSTR_TIME_GET_NANOSEC(t) \ - pg_ticks_to_ns(t) - +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + (pg_ticks_to_ns(ticks)) #else /* WIN32 */ /* Use QueryPerformanceCounter() */ +#define PG_INSTR_CLOCK_NAME "QueryPerformanceCounter" /* helper for INSTR_TIME_SET_CURRENT / INSTR_TIME_SET_CURRENT_FAST */ static inline instr_time @@ -265,8 +268,8 @@ GetTimerFrequency(void) #define INSTR_TIME_SET_CURRENT(t) \ ((t) = pg_query_performance_counter()) -#define INSTR_TIME_GET_NANOSEC(t) \ - ((int64) ((t).ticks * ((double) NS_PER_S / GetTimerFrequency()))) +#define INSTR_TIME_TICKS_TO_NANOSEC(ticks) \ + ((int64) ((ticks) * ((double) NS_PER_S / GetTimerFrequency()))) #endif /* WIN32 */ @@ -285,9 +288,14 @@ GetTimerFrequency(void) #define INSTR_TIME_SUBTRACT(x,y) \ ((x).ticks -= (y).ticks) +#define INSTR_TIME_DIFF_NANOSEC(x,y) \ + (INSTR_TIME_TICKS_TO_NANOSEC((x).ticks - (y).ticks)) + #define INSTR_TIME_ACCUM_DIFF(x,y,z) \ ((x).ticks += (y).ticks - (z).ticks) +#define INSTR_TIME_GET_NANOSEC(t) \ + (INSTR_TIME_TICKS_TO_NANOSEC((t).ticks)) #define INSTR_TIME_GET_DOUBLE(t) \ ((double) INSTR_TIME_GET_NANOSEC(t) / NS_PER_S) -- 2.47.3 --vtqqtrpooseurzip-- ^ permalink raw reply [nested|flat] 265+ messages in thread
end of thread, other threads:[~2025-07-27 15:48 UTC | newest] Thread overview: 265+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2023-10-22 02:22 [PATCH v10 5/7] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]> 2025-07-27 15:48 [PATCH v12 3/3] pg_test_timing: Add --fast flag to test fast timing, report time source Lukas Fittl <[email protected]>
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